SOILS OF MOUND HEDGES IN SCHLESWIG-HOLSTEIN .2. COMPOSITION AND TRANSFORMATION OF SOIL ORGANIC-MATTER

Two Cumulic Anthrosols of mound hedges and the fossil A-horizons below the deposits, were investigated by means of wet chemistry and C-13-NMR spectroscopy in order to characterize soil organic matter (SOM) and to compare their SOM with natural and recent-soils. The bulk humus of the Cumulic Anthrosols contains a high amount of easily soluble polysaccharides. Despite their high bioavailability sugars, starch and mobile fulvic acids are not completely consumed by microorganisms and translocated into the subsoil. The initial phase of podzolization is indicated due to this process and the very low pH-level of the soils. After deposition about 30% of the soil carbon in the A-horizons is mineralized Litter compounds are predominantly decomposed, whereas humic compounds are selectively preserved or newly synthesized. The significance of the humic compounds in the soil organic matter increases after deposition. This is why the potential cation exchange capacity of the fossil A-horizons is similar to this of the recent ones.